U.S. Pat. No. 6,531,371, granted Mar. 11, 2003, to Hsu et al., for Electrically Programmable Resistance Cross Point Memory, describes a memory device having an active layer of perovskite material interposed between upper electrodes and lower electrodes. A bit region located within the active layer at the cross point of an upper electrode and a lower electrode has a resistivity that can change through a range of values in response to application of one, or more, voltage pulses. Voltage pulses may be used to increase the resistivity of the bit region, decrease the resistivity of the bit region, or determine the resistivity of the bit region. Memory periphery circuits are provided to aid in the programming and read out of the bit region.
U.S. Pat. No. 6,693,821, granted Feb. 17, 2004, to Hsu et al., for Cross-talk Electrically Programmable Resistance Cross Point Memory, describes a memory device having a bit formed using a perovskite material interposed at a cross point of an upper electrode and lower electrode. Each bit has a resistivity that can change through a range of values in response to application of one, or more, voltage pulses.
U.S. Patent Publication No. 2003/142578 A1, of Hsu et al., for Electrically Programmable Resistance Cross Point Memory, published Jul. 31, 2003, describes a memory device having an active layer of perovskite material interposed between upper electrodes and lower electrodes. Voltage pulses may be used to increase the resistivity of the bit region, decrease the resistivity of the bit region, or determine the resistivity of the bit region.
A prior art cross point resistor memory array 10 is depicted in FIGS. 1-3. FIG. 1 is a top plan view of the array, while FIG. 2 is a cross-section taken along line 2-2 of FIG. 1, and FIG. 3 is a cross-section taken along line 3-3 of FIG. 1. Array 10 includes an oxide layer 12, a top electrode 14, a CMR layer 16, a barrier layer 18, a bottom electrode 20, a P+ layer 22, a N+ layer 24 and a silicon substrate 26. CMR memory material 16 is etched using top electrode 14 as a mask. Therefore, along the 2-2 cross-section, the CMR memory material has not been etched, and the CMR material is therefore a continue plate in the 2-2 direction, as shown in FIG. 2. This allows potential cross-talk between adjacent bits in the 2-2 direction.
Liu et al., Electric-pulse induced reversible resistance change effect in magnetoresistive film, Applied Physics Letters, Vol. 76, number 19, p. 2749, May 2000, describes the properties of colossal magnetoresistance (CMR) materials.